Case of West Nile virus prompts city, Union Township to take action against mosquitoes

A Mount Pleasant resident has been hospitalized with the West Nile Virus, prompting city officials to find a way to combat a growing mosquito population.

Mayor Sharon Tilmann said the city commission has been cooperating with Union Township to look into pest control methods for the following fiscal year. This effort is still in the early stages, with no costs or methods determined yet.

"We have more calls from people who want us to do something about mosquitoes," Tilmann said. "So, we thought 'it’s a pest and now it's become a health hazard,' so we wanted to explore spraying."

Interim City Manager Nancy Ridley said once the cost and method is determined, the next step will be to reach out to the community to see if this is a service they would be interested in receiving.

Ridley added that she has heard from commissioners and that there have been concerns about the potential harm in using aerosol chemical sprays. However, there is a vocal group of citizens who are in favor of spraying pesticides or other chemical deterrents.

There are several different chemical compounds that can be used in mosquito abatement, making it more likely that the city will contract a company who specializes in population control, speculated Doug Allan, vice president of The Michigan Mosquito Control Association and the head of the Midland County Mosquito Control.

The use of chemical agents is likely because biological controls through the introduction of natural predators is not evaluated as especially effective by the Department of Natural Resources.

This summer has provided particularly fertile conditions for the growth of mosquito populations.

Allen said the last few years have been particularly bad, with heavy spring rain helping produce a lot of pesky bloodsuckers early in the season.

"We had mosquito larvae in the standing water when there was still snow and ice this year, the season starts earlier than people realize and there are many different types," he said. "The more rain we get, the more mosquitoes. Warmer temperatures make them more active."

Allen said all of this increases the chance of contracting the West Nile virus.

Agents of Infection

In Michigan, the West Nile virus was first detected in bird populations a little over a decade ago. Historically, the disease is most prevalent in Michigan’s urban and suburban areas – an average of 85% of all human West Nile cases occur in Kent county and the Metro-Detroit area.

In 2013, there were 36 cases of Human West Nile virus infections reported, resulting in two deaths. Isabella Country reported one case that year. The case was considered "non-neuroinvasive," a less serious classification that causes headache symptoms, muscle and joint pain, rashes or gastrointestinal symptoms.

Robert Graham, medical director for the Central Michigan District Health Department, said each year the number of cases varies between a small handful to a few dozen. He said there are many people who have the disease but are asymptomatic and a majority of cases are not fatal.

The virus can also cause inflammation of the brain, however, according to the Central Michigan District Health Department, the risk of this is low and even more so in persons 50 years of age and younger.

Michigan’s main vector are birds, especially the Corvid family of crows, ravens and blue jays, who are highly susceptible to infection and are surveilled to gauge the prevalence of the disease.

Prevention

Graham said there is no antiviral treatment for the West Nile virus. In more severe cases, symptoms can be managed through intravenous fluids, respiratory support and the prevention of secondary infections.

"I just cant imagine ever getting rid of it unless we have some kid of second ice age or something like that," Graham said. "It's part of the infectious disease soup that we live in, so to speak. People have to be aware of it and take efforts to avoid mosquitoes."

Tilmann said she would meet with Union Township officials sometime in July to discuss the results of their exploration. For now, the city continues to look at the feasibility of such an undertaking.

Allen said there are several simple things individuals can do to protect themselves. Easy tasks like keeping screens repaired to removing standing water on their property can go a long way, he said.

"On a larger scale, that's where you have an advantage," Allen said. "Mosquitoes fly and don't respect property boundaries, so to do a whole neighborhood is more effective than individual yards. A lot of the organized districts come down to the what the local government can afford do"